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Bug 24221 - [XQ3.0] FLWOR expression semantics
Summary: [XQ3.0] FLWOR expression semantics
Status: RESOLVED FIXED
Alias: None
Product: XPath / XQuery / XSLT
Classification: Unclassified
Component: XQuery 3.0 (show other bugs)
Version: Last Call drafts
Hardware: PC All
: P2 normal
Target Milestone: ---
Assignee: Jonathan Robie
QA Contact: Mailing list for public feedback on specs from XSL and XML Query WGs
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2014-01-07 14:56 UTC by Michael Kay
Modified: 2014-02-17 11:01 UTC (History)
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Description Michael Kay 2014-01-07 14:56:13 UTC
In section 3.10 it is stated:

Conceptually, the initial clause generates a tuple stream. Each intermediate clause takes the tuple stream generated by the previous clause as input and generates a (possibly different) tuple stream as output.

In this sentence, "the initial clause" means "the first clause", while "Each intermediate clause" means each clause after the first, before the "return". That is, they don't mean the same as InitialClause and IntermediateClause in the grammar.

A recent thread on xquery-talk suggests that this has been misread and has caused confusion.
Comment 1 Jonathan Robie 2014-02-17 11:01:47 UTC
I propose to close this with the following text:

Delete: A FLWOR expression consists of an initial clause, zero or more intermediate clauses, and a final clause.

Rewrite: Conceptually, the first</phrase> clause generates a tuple stream. Each  clause between the first clause and the return clause takes the tuple stream generated by the previous clause as input and generates a (possibly different) tuple stream as output. The return clause takes a tuple stream as input and, for each tuple in this tuple stream ...